Download Biology Mid-term Study Guide

Biology Mid-term Study Guide
***A link for the notes may be accessed by going to the Biology Mid-term link on the left hand
side of Mrs. Boylan’s website homepage.
CELL CYCLE
Cells have distinct phases of __________________, ___________________________, and
_______________________________________.
• The cell cycle is a regular pattern of _________________, ____________ replication,
and ___________________________________.
• The main stages of the cell cycle are gap 1, synthesis, gap 2, and mitosis.
• _________________ (G1): cell growth and normal functions
• ________________________ (S): copies DNA
• ________________ (G2): additional growth
• __________________ (M): includes division of the cell nucleus (mitosis) and division of
the cell cytoplasm (cytokinesis)
• Mitosis usually occurs only if the cell is large enough and the DNA undamaged.
Cells divide at different rates.
• The rate of cell division varies with the ________________ for those types of cells.
Examples:
• Some cells are unlikely to divide (G0).
Cells divide during ____________________ and _________________________.
Chromosomes condense at the start of _______________________.
• DNA wraps around proteins (histones) that condense it.
Supercoiled DNA
• DNA plus proteins is called _______________________.
• One half of a duplicated chromosome is a _______________________.
• Sister chromatids are held together at the ________________________.
• _______________________ protect DNA and do not include genes.
Mitosis and cytokinesis produce two genetically identical daughter cells.
• ________________________ prepares the cell to divide.
• During interphase, the DNA is ________________________.
Mitosis divides the cell’s nucleus in four phases.
1. During _________________________, chromosomes condense and spindle fibers form.
2. During ___________________________, chromosomes line up in the middle of the cell.
3. During __________________________, sister chromatids separate to opposite sides of
the cell.
4. During telophase, the new nuclei form and chromosomes begin to uncoil.
Cytokinesis differs in animal and plant cells.
• In ____________________________cells, the membrane pinches closed.
• In _________________________ cells, a cell plate forms.
Cell cycle ______________________________ is necessary for healthy growth.
Factors inside & outside cell can regulate cell division.
• Death of nearby cells can _____________________ up cell division.
• Proteins & hormones can both _______________________ and/or
_________________________ cell division.
• Overcrowding can ______________________ cell division.
_________________________ is programmed cell death.
• a _______________________ feature of healthy organisms
• caused by a cell’s production of self-destructive enzymes
• Human embryos have ___________________________ between their fingers and toes.
Before the baby is born the cells undergo apoptosis and they are born with
______________________________fingers and toes.
Cell division is uncontrolled in _____________________________.
• Cancer cells form disorganized clumps called ________________________.
• Benign tumors remain clustered and can be removed.
• Malignant tumors metastasize, or break away, and can form more tumors.
• _____________________________ are substances known to promote cancer.
• Standard cancer treatments typically kill both cancerous and healthy cells.
Many organisms reproduce by cell division.
Binary fission is similar in function to mitosis.
• _____________________ reproduction is the creation of offspring from a single parent.
• Binary fission produces two daughter cells genetically _____________________ to the
parent cell.
• Binary fission occurs in _________________________ (cells without a nucleus).
Cells work together to carry out complex functions.
Multicellular organisms depend on interactions among different cell types.
• _________________________ are groups of cells that perform a similar function.
• ___________________ are groups of tissues that perform a specific or related function.
• __________________________________ are groups of organs that carry out similar functions.
Specialized cells perform specific functions.
• Cells develop into their mature forms through the process of cell _________________
____________. Cells differ because of genes and location in an embryo.
• __________________ cells have the ability to:
-divide and renew themselves
-remain undifferentiated in form
-develop into a variety of specialized cell types
The use of stem cells offers many current and potential _________________________.
• Stem cells are used to treat leukemia and lymphoma.
• Stem cells may cure disease or replace damaged organs.
• Stem cells may revolutionize the drug development process.
___________________________(sex cells) have ________________ the number of
chromosomes that body (somatic) cells have.
Your cells have autosomes and sex chromosomes.
• Your body cells have ___________ pairs of chromosomes; ________________________
pairs of chromosomes have the same structure; for each homologous pair, one
chromosome comes from each parent.
• Chromosome pairs 1-22 are __________________________.
• Sex chromosomes, ______and ______, determine ____________________ in mammals.
Body cells are diploid; gametes are haploid.
•
Fertilization between egg and sperm occurs in sexual reproduction.
• ______________________ (2n) cells have _________ copies of every chromosome.
• Body cells are diploid.
• Half the chromosomes come from each parent.
• _______________________ (n) cells have one copy of every chromosome.
• Gametes are haploid.
• Gametes have 22 autosomes and 1 sex chromosome.
• Meiosis differs from mitosis in significant ways.
• Meiosis has ________ cell divisions while mitosis has ________.
• In mitosis, homologous chromosomes never pair up.
• Meiosis results in haploid cells; mitosis results in diploid cells.
Mendel’s research showed that traits are inherited as distinct units.
Mendel laid the groundwork for_________________________.
• Traits are distinguishing characteristics that are inherited.
• _______________________ is the study of biological inheritance patterns and variation.
• _______________________________ showed that traits are inherited as discrete units.
• Many in Mendel’s day thought traits were blended.
Mendel’s data revealed patterns of inheritance.
• Mendel made _________________key decisions in his experiments.
-use of purebred plants
-control over breeding
-observation of seven “either-or” traits
• Mendel used pollen to fertilize selected ____________ plants.
• P generation crossed to produce F1 generation
• interrupted the self-pollination process by removing male flower parts
• Mendel allowed the resulting plants to self-pollinate.
• Among the ____________ generation, all plants had purple flowers
• F1 plants are all heterozygous (same gene type expressed)
• Among the F2 generation, some plants had purple flowers and some had white
The same gene can have many versions.
• A _________________ is a piece of DNA that directs a cell to make a certain protein.
• Each gene has a locus, a specific position on a pair of homologous chromosomes.
• An ___________________ is any alternative form of a gene occurring at a specific locus
on a chromosome.
• Each parent donates one allele for every gene.
• Homozygous describes two alleles that are the same at a specific locus (location on DNA).
• Heterozygous describes two alleles that are different at a specific locus.
Genes influence the development of traits.
• All of an organism’s genetic material is called the _______________________.
• A _________________________ refers to the makeup of a specific set of genes.
• A __________________________ is the physical expression of a trait.
• Alleles can be represented using letters.
-A ________________ allele is expressed as a phenotype when at least one allele is dominant.
-A ________________ allele is expressed as a phenotype only when two copies are present.
-Dominant alleles are represented by ________________________ letters; recessive
alleles by _________________________ letters.
Punnett squares illustrate genetic crosses.
• The Punnett square is a grid system for predicting all possible genotypes resulting from
a cross.
• The axes represent the possible gametes of each parent.
• The boxes show the possible genotypes of the offspring.
• The Punnett square shows the possible genotypes and phenotypes. Usually shown as a
percentage or fraction.
Heredity patterns can be calculated with probability.
• _____________________________ is the likelihood that something will happen.
• Probability predicts an average number of occurrences, not an exact number of
occurrences.
• Probability = # of ways a specific event can occur
# of total possible outcomes
***Online practice with Punnett squares:
http://glencoe.mheducation.com/sites/0078778066/student_view0/chapter5/math_practice.html
http://anthro.palomar.edu/mendel/quizzes/mendqui2.htm