Name: Life Science Review Packet What Defines Life: An is anything capable of carrying on the processes or characteristics of life. = using materials from the surroundings to make more of oneself, or becoming a larger organism. = a series of changes an organism undergoes as it matures into an adult form, or becoming a more complex organism. All organisms undergo reproduction. reproduction is the reproductive process that involves only one parent and produces offspring that are genetically identical (clones) of that parent. reproduction involves two parents who combine their genetic material to produce a new organism. All living things are made of cells. A is a small building block that is the basic unit of structure and function in all living things. Or, the smallest units of life. A organism, or single celled organism, is composed of only one cell. It can perform all processes necessary for survival. A bacterial cell is the most common example of a unicellular organism. Other examples include amoebas and paramecium A organism is composed of many cells. The cells of multicellular organisms are specialized to perform certain tasks and there is a division of labor among cells to carry out life functions. All cells have or deoxyribonucleic acid. Deoxyribonucleic Acid is a complex molecule found in all living things. The function of DNA is to store and transmit genetic information (genes) that instruct all cell activities including the formation of proteins a basic cell building block. Cells NEED to grow, repair and perform all of the necessary functions for survival. Each cell is able to: obtain chemical energy, convert chemical energy, and use chemical energy to maintain itself, grow, repair, and produce more cells. This capacity is called. All organisms react to changes in their environment. Plants will lean to face the sun, birds fly south for the winter, some animals will shiver if they are cold, or sweat when they are overheated. A is an action or change in behavior that occurs as a result of a stimulus. A is a change in the organism s surroundings that causes the organism to react. All living things maintain a stable internal environment, or a state of balance. This state of balance is called. Cell Structure and Function: Cells are the smallest unit of life that can replicate themselves independently. Complex cells have a true nucleus. A is an example of a eukaryotic organism. cells lack a true nucleus. An example is. The nucleus is a membrane covered organelle that contains most of the cells or deoxyribonucleic acid which contain the that regulate the cells activities. The is filled with complicated structures called organelles that help the cell to function. The cytoplasm (a jelly-like fluid) and organelles are always enclosed in a plasma membrane also known as the membrane. Plants, fungi and bacteria also contain a tough outer cell. Animal cells do not have a cell wall. The cells of multi-celled organisms are often arranged into layers called. The tissues are often arranged into complicated. Organs work together with other to create organ systems. All organ systems function as an organism. Viruses are not considered to be. Review Quiz Animal and Plant Cell Organelles/Structures: Nucleus contains DNA and tightly wound chromosomes. Lysosomes and peroxisomes break down the cell s waste products and detoxify poisons. Cell (plasma) membrane controls what molecules enter and leave the cell. Endoplasmic reticulum a network of folds dotted with ribosomes, which make proteins. It ships these proteins to the cell membrane or to other organelles including the golgi bodies. Cytoplasm is a fluid that maintains the internal pressure of the cell, and holds many important nutrients and organelles. Mitochondria are organelles that produce a molecule called ATP, which serves as fuel for the cell. Golgi Apparatus: Like a packaging plant, this organelle puts lipids and proteins in packets (vesicles), and sends them to different parts of the cell. Ribosomes: Tiny organelles that follow instructions from the nucleus and create proteins that the cell needs. Plant Cell Organelles/Structures: Chloroplasts: Chloroplasts convert the sun s energy into chemical energy (glucose). Cell Wall: rigid outer layer that protects the cell and maintains the cells shape. Vacuole: water, nutrient and waste storage site.
Plant Cell - eukaryotic Animal Cell - eukaryotic Cell or plasma membrane Cell Theory: Three German scientists, Matthias Schleiden, Theodor Schwann, and Rudolf Virchow were instrumental in development of what is called the cell theory. In 1838 Schleiden said that all plants were made from cells. In 1839 Schwann said all animals were made from cells, and in 1855 Virchow said that all cells come from other cells. The development of the cell theory has been dependent upon improvements in the microscope and microscopic techniques throughout the last four centuries. The cell theory states: 1. All living things are composed of. 2. Cells are the basic units of structure and function in things. 3. All are produced from other cells. The cell theory disproved the idea of spontaneous generation which is the belief that living things can arise from the non-living. Cell Processes Cell Division Mitosis: is a type of cell division that results in daughter cells each having the number and kind of chromosomes as the parent nucleus, typical of ordinary somatic (body) cell growth. The purpose is to produce new cells for growth and repair that are identical to the parent cell. 1. Interphase: Is the longest stage of the cell cycle. Cells grow, replicate (copy) DNA, and undergo normal function. 2. Mitosis: Active cell division. The nucleus disappears, chromatin thickens and become chromosomes, spindle fibers connect chromosomes from centrioles to centromeres. Chromosomes split apart at centromeres and move to each side of the cell. PMAT = prophase, metaphase, anaphase, telophase (the individual phases of mitosis). 3. Cytokinesis: The last stage of the cell cycle in which the cytoplasm divides forming two new cells, each having its own nucleus, cytoplasm and cell membrane. Bacterial Cell - prokaryotic Cell Division Meiosis: Is a type of cell division which reduces the chromosome count to half of the original number of the parent cell. The purpose is to produce gametes, or sex cells. At the end of meiosis sperm cells are created in males and egg cell plus polar bodies (nonfunctioning cells) are created in females. Meiosis creates genetic diversity, or distinctly unique organisms that are a product of two different sets of genetic material.
2. Osmosis: Osmosis is the movement of from a high concentration to a low concentration across a semipermeable membrane. 3. Facilitated Diffusion: Facilitated diffusion is the process of spontaneous transport of molecules or ions across a membrane through specific membrane channels. Cell Processes Continued The Cell Membrane and Permeability: Cell membranes are selectively permeable, meaning that they will allow certain substances to through while forming a barrier against others. It is a quality of a cell s membrane that allows substances to pass in and out of it, so that the cell can waste products and ship out the chemicals and other nutrients that it assembles for the body. At the same time, the nutrients that the cell needs can pass through the membrane to the inside. Lipid Bilayer of the Cell Membrane Active Transport: Active transport is the movement of molecules across a cell membrane the normal concentration gradient, i.e. moving from an area of lower concentration to an area of concentration, WITH the use of energy. Three Types of Passive Transport of Materials: 1. Simple Diffusion: The net movement of substances from a region of concentration to a region of concentration. Generally, simple diffusion of water, gases, and other small, uncharged molecules across plasma (cell) membranes without the use of energy. SUMMARY Passive Transport = No Energy Required Active Transport = Energy Required
Cell Processes Continued Photosynthesis: Photosynthesis is a process used by plants and other organisms to convert energy, normally from the Sun, into chemical energy that can be later released to fuel the organisms' activities. Photosynthesis occurs in the chloroplasts of the plant cell wherein green pigments called chlorophyll absorb and light energy. The balanced equation for photosynthesis is written as: DNA Structure and Function DNA is a helix model that includes four different components: sugars, nitrogenous bases, and phosphates. The arrangement of the nitrogenous bases within the double helix forms a chemical. 6CO2 + 6H2O ------> C6H12O6 + 6O2 Sunlight energy Plants are called producers because of their ability to obtain energy from the sun and convert this energy into glucose (sugar). Photosynthesizing organisms are the foundation of virtually food webs. Chromosomes are tightly wound. Genes are sections of a chromosome that carry the code for a particular trait. An allele is an alternate form of a gene. Cellular Respiration: Cellular respiration is the process of oxidizing (using oxygen to break down) molecules, like glucose, to carbon dioxide and water. The energy released is trapped in the form of for use by all the energy-consuming activities of the cell. The balanced equation for photosynthesis is written as: C₆H₁₂O₆ + 6O₂ 6CO₂ + 6H₂O + energy In eukaryotic organisms, DNA is located within the of the cell. In prokaryotic organisms the DNA is located in a region called a nucleoid (not a true nucleus)
DNA Continued Questions: 1. Who made X-ray diffraction images of DNA? 2. Which two scientists won the Nobel Prize for their discovery of the double helix shape of DNA? DNA and Heredity Genetics is the study of, heredity and genetic variation in living organisms. The father of genetics is Gregor Mendel, a late 19 th century scientist who studied how are handed down from parents to offspring. The basic laws of Mendelian genetics explain the transmission of most traits (not all) that can be inherited from generation to generation through. Characteristics that are acquired from the environment (dyed hair, a learned skill like language) are NOT inherited. Mendels Findings: 1. There are two alleles for every trait 2. Dominant traits mask the expression of Recessive traits. 3. Recessive traits will appear only when both recessive alleles have been inherited. Vocabulary: Homozygous Dominant: Two Dominant alleles for a trait (written for example as TT) Homozygous Recessive: Two Recessive alleles for a trait (written for example as tt) Heterozygous: One Dominant and one Recessive allele for a trait (written for example as Tt) Purebred: Both alleles are identical indicating only one form of a trait is inherited - either both dominant (TT), or both recessive (tt) Hybrid: One dominant and one recessive allele are inherited (Tt) Phenotype: The physical appearance of the trait (brown hair, blue eyes for example) Genotype: The alleles that have been inherited (Two dominant genes BB for example) Complete the following Punnett Squares Traits Studied: Purple flowers (dominant) crossed with white flowers (recessive) PP X pp A square is a model used to predict the possible combinations of inherited factors resulting from single trait crosses. Percentage of offspring that will have purple phenotype Percentage of offspring that will have white phenotype Percentage of offspring that will be homozygous dominant Percentage of offspring that will be homozygous recessive Percentage of offspring that will be heterozygous Percentage of offspring that will be hybrid Percentage of offspring that will be purebred List genotypes of offspring:
Complete the following Punnett Squares Traits Studied: Round seeds (dominant) crossed with wrinkled seeds (recessive) Rr X rr Percentage of offspring that will have brown eye phenotype Percentage of offspring that will have blue eye phenotype Percentage of offspring that will be homozygous dominant Percentage of offspring that will be homozygous recessive Percentage of offspring that will be heterozygous Percentage of offspring that will be hybrid Percentage of offspring that will be purebred List genotypes of offspring: Percentage of offspring that will have round phenotype Percentage of offspring that will have wrinkled phenotype Percentage of offspring that will be homozygous dominant Percentage of offspring that will be homozygous recessive Percentage of offspring that will be heterozygous Percentage of offspring that will be hybrid Percentage of offspring that will be purebred List genotypes of offspring: Genetic Engineering In genetic engineering the genetic is manipulated to obtain a desired product. Genetic engineering does not include the selective breeding practices used by farmers and horticulturists for centuries. Genetic engineering involves the of genes from one organism that will be inserted into the genome of an entirely different organism. Genetic engineering has numerous practical applications in medicine, agriculture, and biology. Examples: Genetically modified organisms (GMO s) which include bacteria that have been genetically modified with the human insulin producing gene. As a result we have bacteria with human genes that produce human insulin. In agriculture, plants such as potatoes have been genetically engineered to produce bacteria toxins that will kill insects with the hopes of reducing the amount of pesticides that are sprayed. Traits Studied: Brown eyes (dominant) crossed with Brown eyes (dominant) Bb X Bb Cloning is a type of genetic engineering in which the offspring are an identical copy of the parent. Dolly the Sheep The first animal to be cloned from a somatic cell