D2 Continuity and change cells

Question 1

What is cell division?

Answer 1

New cells are produced by the division of pre-existing cells – dividing cell is called the mother cell and it produces two daughter cells

Question 2

What is cytokinesis and how does it differ in animal and plant cells?

Answer 2

Cytokinesis is the division of a cell’s cytoplasm to form two cells. Animal: cytoplasm is divided by moving the plasma membrane. Plant: New cell wall is made across the cell’s equator

Question 3

Equal vs. unequal cytokinesis

Answer 3

Equal (most cases, division into equal halves), unequal (budding in yeast - receives nuclei but only a little cytoplasm, oogenesis in humans - eggs (oocytes) are needed less so division produces one large cell and polar bodies

Question 4

Two types of nuclear division in cells:

Answer 4

Mitosis (asexual reproduction, all chromosomes are received from mother), Meiosis (sexual reproduction – diploid nucleus divides into haploid nuclei)

Question 5

DNA replication and the state of DNA after

Answer 5

During replication, DNA is in an elongated state, then condensation makes the two DNA structures into separate structures (sister chromatids), separated into separate poles

Question 6

Stages of mitosis

Answer 6

IPMAT: Interphase (elongated DNA in the middle), Prophase (shorter DNA in the middle), Metaphase (attaching into spindle microtubules, still in the middle), Anaphase (microtubules link and pull chromosome to pole), Telophase (membrane formed around chromosome poles)

Question 7

how are diploid cells produced

Answer 7

fusion of gametes, each of which contains haploid number of chromosomes

Question 8

Why is meiosis called reduction division

Answer 8

Because genetic material is halved from diploid (2n) to haploid (n) before reproduction

Question 9

Why are there more stages to meiosis

Answer 9

Because the cells need to be divided into four instead of one to produce half of the original material

Question 10

Two ways that meiosis generates variation

Answer 10

1. random orientation of bivalents (many combinations can be formed when homologous chromosomes separate in anaphase I), 2. crossing over (homologous chromosomes pair up and non-sister chromatids exchange lengths of DNA by crossing over during early stages of meiosis)

Question 11

Solvent

Answer 11

Liquids that dissolve other substances to make solutions

Question 12

Solute

Answer 12

Dissolved in other substances

Question 13

Water as a solvent

Answer 13

Water dissolves many different types of molecules by forming hydrogen bonds with them – also dissolves ions because poles of water molecules are attracted to both positive and negative charges

Question 14

Hypotonic, hypertonic and isotonic solutions

Answer 14

hypo = lower solute concentration, hyper = higher, iso= same

Question 15

Movement of water in solutions

Answer 15

more net movement from hypo to hyper due to water’s attraction to the solutes

Question 16

Osmosis

Answer 16

Passive movement of water through plasma membrane (separating inside from extracellular fluids, semi-permeable aka not to all particles) which can control the amount of permeability to water and change pace of osmosis

Question 17

Why are isotonic solutions used in medicine

Answer 17

Because osmosis can cause cells in human tissues to swell and burst or shrink and die