Unit 5 - Heredity

Question 1

Gametes

Answer 1

• a sex cell ( sperm or an egg)
• designated by the n number

Question 2

What are gametes made by?

Answer 2

meiosis

Question 3

Gametogenesis

Answer 3

the process in which cells undergo meiosis to make sex cells

Question 4

Haploid Number

Answer 4

n - number of chromosomes

Question 5

Oocyte

Answer 5

egg cell

Question 6

Fertilization

Answer 6

• sperm and egg meet (sperm enters egg)
• restores the diploid number (2n) bc two haploid gametes each containing half the number of chromosomes (the haploid number), combine to form a diploid.

Question 7

Diploid

Answer 7

• a number of chromosomes in in a body cell
• 2n

Question 8

Body cells

Answer 8

somatic cells - autosomes

Question 9

autosomes

Answer 9

are the chromosomes that determine traits other than sex (e.g., eye color, height, metabolism).

Question 10

Somatic Cells

Answer 10

are all the cells in your body except gametes (sperm and egg cells).

Question 11

Karyotype

Answer 11

picture of the chromosomes

Question 12

Homologous Chromosomes

Answer 12

separate chromosomes (NOT DUPLICATED CHROMOSOMES) that code for the same type of genes (ex. height )
- inherited

Question 13

Mitosis

Answer 13

produces 2 genetically identical cells

Question 14

Meiosis

Answer 14

produces gametes ( provides variety )

Question 15

Interphase (part of S-phase)

Answer 15

• start with 6 chromosomes and duplicate the chromosomes
• in the end we should have 4 haploid cells with half chromosomes in each so 3 in each

Question 16

Meiosis 1 ( the first division )
Prophase 1

Answer 16

• chromosomes condense
• homologous chromosomes pair up (one from dad and one from mom)
• recombination of genes (when they pair up they combine to make tetrad and chiasma

Question 16

Synapsis in Prophase 1

Answer 16

when the homologous chromosomes pair up (one from dad and one from mom)

Question 17

Tetrad in Prophase 1

Answer 17

is created when two homologous chromosomes (one from each parent) pair up.
Each chromosome in the pair has two identical sister chromatids. Together, that makes 4 chromatids total, hence the name “tetrad.”

Question 18

Chiasma

Answer 18

physical site where homologous chromosomes overlap and swap DNA. So this is where they are touching and where they recombine to get that variety

Question 19

Meiosis 1
Metaphase 1

Answer 19

the homologous chromosomes line up

Question 20

Law Of Independent Assortment

Answer 20

chromosomes can line up in many different arrangements

Question 20

Meiosis 1
Anaphase 1

Answer 20

• homologous chromosomes separate
• if chromosomes don’t separate correctly then you have non-disjunction which is uneven distribution of chromosomes

Question 20

Meiosis 1
Telophase 1

Answer 20

two haploid cells are made and they are genetically different

Question 20

Why do the chromosomes go straight to prophase and not to interphase when you go to meiosis 2?

Answer 20

After Meiosis I, the sister chromatids are already present, so there’s no need to replicate the DNA again before Meiosis II.

Question 20

Meiosis 2 Prophase 2

Answer 20

nuclear envelope breaks down

Question 21

Meiosis 2 Metaphase 2

Answer 21

chromosomes line up

Question 21

Meiosis 2 Anaphase 2

Answer 21

the sister chromatids pull apart

Question 22

Meiosis 2 Telophase and Cytokinesis

Answer 22

both cells divide again, making four unique haploid cells. and now we make sex cells so 4x sperm, 1x egg, and 3x polar bodies that are useless

Question 23

polar bodies

Answer 23

small non-usable cells that do not fertilize and they get reabsorbed into the body

Question 24

Law Of Segregation

Answer 24

genes that go into gametes sort randomly and this allows for variety

Question 25

Autosomal Inheritance

Answer 25

inherit 2 of every kind

Question 26

Phenotype

Answer 26

observable characteristics so what protein is being made and expressed

Question 27

Genotype

Answer 27

actual gene that codes for a protein to express phenotype

Question 28

Allele

Answer 28

- different forms of a gene - ex. you receive brown hair from mom and blond hair from dad

Question 29

How does genotype determine phenotype

Answer 29

genotypes code for the production of a protein and that protein gives our physical traits

Question 30

Homozygous dominant

Answer 30

An individual has two dominant alleles for a gene (e.g., AA).

Question 31

Heterozygous

Answer 31

An individual has one dominant allele and one recessive allele for a gene (e.g., Aa).

Question 32

Homozygous recessive

Answer 32

An individual has two recessive alleles for a gene (e.g., aa).

Question 33

Locus

Answer 33

specific location of a gene

Question 34

On the genetic level what is happening?

Answer 34

- gene codes for a protein - gene gets transcribed into mRNA - mRNA goes to the ribosomes to make a protein

Question 35

Homozygous dominant (true breeding)

Answer 35

Two dominant alleles for a trait (AA). Always passes on the dominant allele to offspring.

Question 36

Homozygous recessive (true breeding):

Answer 36

Two recessive alleles for a trait (aa). Always passes on the recessive allele to offspring.

Question 37

Heterozygous (hybrid):

Answer 37

One dominant and one recessive allele for a trait (Aa). Displays the dominant trait but can pass on either allele to offspring.

Question 38

Carrier

Answer 38

A heterozygous individual for a recessive trait (Aa) that does not express the recessive condition but can pass the recessive allele to offspring.

Question 39

Wild Type

Answer 39

the original/ natural form of a gene

Question 40

Blood Clotting

Answer 40

- original form: blood clotted and clot broke down - mutated: blood clots and clots and clots

Question 41

Phenotypic ratio

Answer 41

9:3:3:1

Question 42

What happens to chromosome numbers in both meiosis 1 and meiosis 2?

Answer 42

The number of chromosomes in a cell is halved during meiosis I and maintained during meiosis II

Question 43

Imcomplete Dominance

Answer 43

neither allele is dominant over the other so its the blending of allele resulting in a new phenotype

Question 44

Co dominance

Answer 44

both alleles are expressed in the heterozygous condition

Question 45

Polygenic Inheritance

Answer 45

multiple genes that will code for one specific phenotype

Question 46

Epistasis

Answer 46

multiple genes that code for a phenotype and one gene that modifies/controls phenotype

Question 47

Linked Traits

Answer 47

genes found on the same chromosome

Question 49

Epistasis

Answer 49

multiple genes that code for a phenotype and one gene that modifies/controls phenotype

Question 50

If genes are located on different chromosomes what does that mean

Answer 50

it means they assort independently and u expect a 1:1:1:1 ratio