D2.1 - cells and nuclear division

Question 1

microtubules

Answer 1

long, thin fibrous proteins that forms the spindle

Question 2

microtubule motors

Answer 2

binds to microtubules & hydrolyses ATP to produce energy to move chromosomes during cell division

Question 3

Budding

Answer 3

asexual reproduction in yeast

• outgrowth of genetically identical daughter cell (bud from parent cell)

Question 4

hydra

Answer 4

genus of small aquatic invertebrates that bud
- rapid increase in population

Question 5

budding scar

Answer 5

determines how old & how many times the cell has divided

Question 6

prokaryotic vs eukaryotic division

Answer 6

prokaryotic: divides by binary fission

eukaryotic: mitosis or meiosis (to create gametes)

Question 7

homozygous

Answer 7

two of the same allele

Question 8

heterozygous

Answer 8

two different alleles

Question 9

mitosis

Answer 9

Mitosis is a type of nuclear division that produces two genetically identical diploid daughter nuclei for somatic cells

Question 10

chromosome

Answer 10

wo genetically identical sister chromatids held together at the centromere.

Question 11

microtubule organising centres (MTOCs)

Answer 11

Structures within cells that regulate the formation and organisation of spindle fibres. (PLANT CELL)

Question 12

centrosomes

Answer 12

a type of MTOC that contains centrioles. MTOCs migrate to each pole (end) of the cell during prophase.

(ANIMAL CELLS)

Question 13

meiosis

Answer 13

type of nuclear division that produces four haploid genetically unique daughter nuclei, which will form gametes for sexual reproduction

Question 14

bivalent/ tetrad

Answer 14

A pair of homologous chromosomes that come together during prophase I of meiosis.

Question 15

homologous pair

Answer 15

Paired chromosomes that have the same genes at the same locations.

Question 16

allele

Answer 16

a variant/ version of a gene

Question 17

Karyotyping

Answer 17

Determining or analysing the karyotype (number, size and shape of the chromosomes) of an individual.

Question 18

chiasmata

Answer 18

points at which crossing over occurs between two non-sister chromatids

Question 19

non-recombinant chromatids

Answer 19

Chromatids that have not undergone crossing over.

Question 20

meristem

Answer 20

Regions of undifferentiated cells at the tips of roots and shoots, in plants, that have the potential to become any cell type in the plant.

Question 21

mutation

Answer 21

changes in DNA sequence

Question 22

cyclins

Answer 22

family of proteins that regulate the cell cycle.
- binds to and activates CDK enzymes that phosphorylate specific proteins.

Question 23

mutation

Answer 23

• change in sequence of genetic material

Question 24

hermaphroditic

Answer 24

An organism with both male and female reproductive organs

ex. pea plant

Question 25

true breeding parents

Answer 25

An organism that always passes on its phenotypic traits to the offspring.

Question 26

genes

Answer 26

segment of DNA that codes for specific protein

Question 27

genotype

Answer 27

• different combinations of alleles

Question 28

phenotype

Answer 28

• physical traits
• outward expression of allele combos with environmental factors

Question 29

SNP

Answer 29

single nucleotide polymorphism
- most common variants in humans
- at single nucleotide/base pair when genome is copied

• can be in a gene that codes for a protein or in parts of the DNA for other functions

Question 30

explain blood type and multiple alleles

Answer 30

• A, B and O allelic forms
• chromosome 9
• ABO gene
• each make their own enzyme that catalyze specific sugars on the outside of the cell
• sugars produce immune response - antigens

Question 31

codominant

Answer 31

2 alleles are both expressed equally - AB blood type

Question 32

incomplete dominance

Answer 32

A third phenotype that is intermediate between the dominant and recessive can be produced.

Question 33

linked vs unlinked

Answer 33

linked - Genes on the same chromosome that are usually inherited together

unlinked - genes on different chromosomes

Question 34

mitotic index

Answer 34

proportion of actively diving cells

Question 35

tumor suppressor genes and protooncogenes in mutations

Answer 35

tumor suppressor genes: code proteins that suppress cell growth
protooncogenes: code proteins to promote cell growth

mutations in those genes cause uncontrolled division

Question 36

Outline the process of cytokinesis in plant and animal cells.

Answer 36

animal cells:
actin and myosin proteins form contractile ring
pinches cell membrane together (fluidity helps)
forms cleavage furrow
plant cells:
cell plate, formed when vesicles (that contain materials) fuse in the middle
forms new cell wall

Question 37

aneuploidy and polyploidy

Answer 37

don’t add to 46. extra or missing chromosome(s)

Question 38

law of segregation

Answer 38

gametes only carry one allele for a gene