Mitosis/Meiosis

Question 1

Meiosis vs mitosis

Answer 1

In mitosis we stay diploid and in meiosis we go from diploid to haploid. There is a different way that the chromosomes rearrange

Question 2

Locus (plural: loci)

Answer 2

Each gene occupies a specific place, or locus, on the chromosome

Question 3

Condensation can be condensed during mitosis

Answer 3

True

Question 4

Centromere

Answer 4

Where two sister chromatids hook together (middle of X)

Top half: p arm
Bottom: q arm

Question 5

Telomere

Answer 5

The two ends of a chromosome consist of repeated nucleotide sequences called telomeres, which are essential for chromosome stability

Question 6

22/23 pairs of chromosomes are called _______

Answer 6

Autosomes

Autosomes have similar appearance and similar DNA sequences, and are paired in diploid cells of both sexes

Question 7

Sex chromosomes

Answer 7

The 23rd pair of chromosomes and is different in the male and female

Question 8

A typical human cell has how many pairs of chromosomes?

Answer 8

23

Question 9

The male X and Y chromosomes behave as a pair during meiotic cell division

Answer 9

True

Question 10

X=chromosome, made up of 2 chromatids

Answer 10

True

Question 11

Further from centromere you get bigger numbers

Answer 11

True

Question 12

Homologous chromosomes are usually not identical

Answer 12

True

Changes are called mutations

Enduring mutations that are inherited are called alleles (different eye color, hair, bird songs etc)

Question 13

Our gametes are only cells that are ______

Answer 13

haploid

Question 14

Interphase

Answer 14

Time for acquisition of nutrients, growth, chromosome duplication

During cell division, one copy of every chromosome and half of the cytoplasm and organelles are divided out into the 2 daughter cells

Question 15

Mitotic cell division

Answer 15

Consists of the division of one parental cell into two daughter cells; it consists of two processes: mitosis and cytokinesis

Question 16

Mitosis

Answer 16

Division of the nucleus

During mitosis (nuclear division), the nucleus of the cell and the chromosome divide

Each daughter nucleus receives one copy of each of the replicated chromosomes of the parent cell

Question 17

Cytokinesis

Answer 17

Cytoplasmic division

Cytoplasm is divided roughly equally between the two daughter cells, and one daughter nucleus enters each of the daughter cells

Question 18

Mitotic cell division

Answer 18

Takes place in all eukaryotic organisms

Mechanism of asexual reproduction

Followed by differentiation of the daughter cells allows a fertilized egg to grow into an adult with perhaps trillions of specialized cells

Allows organisms to maintain, repair, and even regenerate body parts

Mechanism whereby stem cells reproduce

Question 19

Prophase

Answer 19

Chromosomes condense, spindle microtubules form, nuclear envelope breaks down, and chromosomes are captured by spindle microtubules

Question 20

Centrioles

Answer 20

Region from which the spindle microtubules originate contains a pair of microtubule-containing structures called centrioles

Question 21

Kinetochore

Answer 21

Protein-containing structure located at the centromere

Wraps around centromere

Question 22

Microtubules

Answer 22

The spindle microtubules radiate from the poles, both toward the nucleus, forming a basket around it and outward toward the plasma membrane

Question 23

Cell cycle has checkpoints

Answer 23

True

Slows it down to make sure enzymes can go double check that everything is correct

Question 24

Cohesin complex

Answer 24

Begin to wrap around DNA

Keeps chromatids attached

Facilitates spindle attachment

Facilitates recombination

Question 25

Gametogenesis

Answer 25

From 46 to 23 chromosomes Meiosis only occurs for making sperm and eggs

Question 26

Meiotic cell division

Answer 26

The key to sexual reproduction in eukaryotic cells A diploid cell with paired chromosomes produces haploid daughter cells with unpaired chromosomes

Question 27

Prophase 1

Answer 27

Homologous chromosomes pair up and exchange DNA

Question 28

One round of DNA replication produces how many chromatids in each duplicated chromosome?

Answer 28

2

Question 29

Prophase I

Answer 29

Can last days or weeks For women it can be occurring during the month

Question 30

Metaphase 1

Answer 30

Paired homologous chromosomes line up at the equator of the cell

Question 31

X chromosome is always the default

Answer 31

True

Question 32

We get 4 equal sperm and only 1 ovum in females, the other 3 are called polar bodies

Answer 32

True

Question 33

Genomic Imprinting

Answer 33

Imprinted genes=methylation=down regulated

Question 34

Chance for mitotic errors

Answer 34

If meiosis doesn't occur until after or during ovulation, then you get improper segregation after fertilization and so you'll get too many chromosomes in egg

Question 35

Nondisjunction

Answer 35

Most common way we get developmental errors in meiosis When we get an abnormal chromosome number - Trisomy 21/Down syndrom: most common single cause of mental retardation - 90% of trisomy 21 individuals, the additional chromosome is maternal in origin - 70% occur during M1 and 30% in M2

Question 36

Prader Willi syndrome and Angelman syndrome

Answer 36

Two different conditions occur with the exact same deletion on chromosome 15. If the paternal chromosome is deleted, the child develops Prader Willi syndrome. If the maternal chromosome is deleted, the child develops Angelman syndrome

Question 37

Prader Willi syndrome

Answer 37

When paternal chromosome is deleted on chromosome 15

Question 38

Angelman syndrome

Answer 38

When maternal chromosome is deleted on chromosome 15

Question 39

More chromosomal errors

Answer 39

Errors on chromosomes 13, 18, 21 cause major developmental defects. Events can occur during non-disjunction You can either have entire copies of chromosomes go to one cell so that when you have division you have an additional chromosome and 2 gametes and a loss of chromosomes and other gametes, or you can have that happen in meiosis 2 and you get two viable eggs and then that same problem

Question 40

Homologous recombination problems

Answer 40

During homologous recombination there is a good chance for errors because you are having a double strand break and so pieces might get not put back correctly. So if mom doesn't express that gene and dad has a deletion, then we have problems.

Question 41

Trisomy 21, 18, 13

Answer 41

Non-disjunction during meiosis. , so you get an extra 21 chromosome Down syndrom=Drinking age=trisomy 21 Edward syndrome = Election age = trisomy 18 Patau syndrome = Puberty age = trisomy 13

Question 42

Lyonization

Answer 42

used to create Barr bodies. Females don't use both X chromosomes in every cell. Creates mosaic pattern. Different regions of body can be using the copy you got from mom and copy from dad

Question 43

Nondisjunction

Answer 43

Homologs fail to separate properly -Nondisjunction errors are very common during egg development and increase with advancing maternal age

Question 44

Trisomy 21/Down syndrome is an example of what type of error?

Answer 44

Aneuploid: cells with abnormal chromosome number – Trisomy 21/Down syndrome: most common single cause of mental retardation. – 90% of trisomy 21 individuals, the additional chromosome is maternal in origin • 70% occur during MI and 30% in MII