Genetics

Question 1

Cell Cycle

Answer 1

G1: cell growth and preparation of chromosomes for replication
G0: crease division
S: synthesis of DNA and duplication of centrosomes
G2: preparation for mitosis

Question 2

Mitosis

Answer 2

Always happening in our body as it create new cells and repairs damaged
46 chromosomes in humans
23 pairs of chromosomes

Question 3

Stage of mitosis

Answer 3

Chromatin condenses into distinct chromosomes
Centrioles move to opposite poles of the cell
Chromosomes are duplicated
New chromosomes are called “sister chromatids”

Question 4

Metaphase

Answer 4

Late prophase chromatids move toward the cell equator

Aligned at the equator

Question 5

Anaphase

Answer 5

Chromatids move apart, opposite poles

After separation they’re called chromosomes

Question 6

Telophase

Answer 6

Chromosomes reach opposite sides

Spindle fivers dissolve

Question 7

Cytokinesis

Answer 7

Division of cytoplasm
Plant cells: new cell wall forms to divide 2 daughter cells
Animal cells: cleavage furrow forms as cell membrane

Question 8

Mitosis

Answer 8

Process of sex cells are created
Involves reduction division, chromosome # is reduced
Meiosis involves 2 divisions: meiosis I and meiosis II

Question 9

Stages of Meiosis I

Answer 9

Duplication of DNA
Crossing over synapsid at chiasma, pairing homologous chromosomes 
Metaphase I:
Homologous chromosomes line up in pairs
Spindle fibres attach centromeres

Question 10

Anaphase I

Answer 10

Separation of homologous chromosomes

Question 11

Telophase I

Answer 11

Chromosomes arrive at spindle poles

Each cell has one homologous chromosome

Question 12

Stages of Meiosis II

Answer 12

Prophase II (no duplication occurs)
Metaphase II (same as metaphase I)
Anaphase II
Centromeres divide 
Sister chromatids separate creating chromosomes

Question 13

Telophase II

Answer 13

Nuclear envelope, forms around each set of chromosomes
Nucleolus appears in each nucleus
Chromosomes lengthen and become indistinct
Cytokinesis occurs forming 4 cells

Question 14

Key terms

Answer 14

Chromosomes: cells nucleus contains DNA. Single piece of DNA that contains genes
Homologous Chromosomes: not genetically identical
Sister Chromatids: identical copies of chromosomes

Question 15

Key terms

Answer 15

Diploid (2N): cell contains 2 sets of chromosomes, one set of chromosomes is donated from each parent
Haploid (1N): complete set of chromosomes gamets
Crossing Over: occurs in prophase I of meiosis I, hemoglobins chromosomes pair up during synapsis.
Ensures no siblings are the same

Question 16

Dominant Alleles

Answer 16

Phenotypes of genetic traits in the offspring

Question 17

Recessive alleles

Answer 17

Less influential due to being masked by dominant alleles

Must have 2 restive alleles for specific trait in an offspring

Question 18

Genotype

Answer 18

Genetic make up
Gene that an organism has for a specific trait
2 alleles combine to determine the expression of a trait
PP = homozygous Dominant
Pp = heterozygous hybrid
pp = homozygous recessive

Question 19

Phenotype

Answer 19

Expression of curtain genes but not others

Question 20

Punnett squares

Answer 20

Shows potential offspring of 2 parents

Diagram that predicts the outcome of particular crosses

Question 21

Incomplete dominance

Answer 21

Neither allele is dominant

Heterozygous condition is a blend of traits

Question 22

Co-Dominance

Answer 22

Both alleles in a heterozygous individual

Expressed at the same time without blending traits

Question 23

Antigens

Answer 23

Proteins on the membrane of every RBC

Question 24

Antibodies

Answer 24

Located in the blood plasma

Response to antigens

Question 25

Blood types

Answer 25

Type A = antigen -A on its membrane Type B = antigen -B on its membrane Type AB = antigen -A & -B on its membrane Type O = NO ANTIGEN!!

Question 26

Symbols for blood

Answer 26

I = dominant i = recessive A&B are dominant

Question 27

Blood combination

Answer 27

Type A = IAIA or IAi Type B = IBIB or IBi Type AB = IAIB Type O = ii

Question 28

Sex linked inheritance

Answer 28

Alleles on sex chromosomes are inherited in predictable patterns Female: XX (homozygous) Male: XY (heterozygous)

Question 29

Sex linked conditions

Answer 29

120 sex linked in humans Colour blindness Hemophilia Male pattern baldness

Question 30

Sex linked traits

Answer 30

If it’s recessive then there’s little chance of it being expressed Males only have one X chromosomes If they receive recessive allele for the trait they will exhibit that phenotype

Question 31

Autosomal recessive

Answer 31

In every generation | Males/females are equally likely to be affected

Question 32

Autosomal recessive

Answer 32

Phenotype skips generation | Males/females equally affected

Question 33

Sex linked dominant

Answer 33

Usually in every generation | Females more often affected then males

Question 34

Sex linked recessive

Answer 34

Phenotype skips generations | Affected males DO NOT pass the condition onto their sons

Question 35

Mitochondrial inheritance

Answer 35

Inherited from the mother Father cannot pass the trait onto progeny Only the daughters will pass the trait to the next generation

Question 36

Chromosome mutations

Answer 36

Monosomy: Aneuploidic condition where you have a single copy of a chromosome

Question 37

Turner syndrome

Answer 37

Women only have one X chromosome Only non lethal case of full monosomy in humans Physical abnormalities: short stature, broad chest, low hair line