Bio M5 IQ2

Which organelle is most DNA found?

nucleus

Cell replication

the process of cell division in order to make new cells and occurs through mitosis and meiosis

Chromosome combination for male

XY

Chromosome combination for female

XX

What does DNA contain instructions for and what does this determine?

making proteins and RNA, determining characteristics inherited

What is the role of proteins?

To carry out tasks necessary for building and maintaining the cell

DNA nitrogen bases and their pairs

Adenine and Thymine

Cytosine and Guanine

What percentage of human's DNA sequences are identical?

99.5%

What factors influence traits?

genes, proteins, DNA

What is the backbone of DNA composed of?

Deoxyribose sugar and phosphate

components making up a nucleotides

- nitrogenous base: purines and pyrimidines

- pentose sugar (deoxyribose)

- phosphate group

Three steps of DNA replication

1. Unwinding

2. Complementary base pairing

3. Joining

Mitosis

process of making now body (somatic) cells for the purpose of growth and repair

Mitosis in humans

parent cell divides to form two genetically identical Diploid daughter cells each containing 46 chromosomes

Meiosis

produces sex cells (gametes) such as sperm and egg for the purpose of sexual reproduction

Meiosis in humans

Parent cell divides to form four genetically unique haploid daughter cells each containing 23 chromosomes

How do daughter cells come to be unique from parent cells?

due to various processes including crossing-over, random segregation and independent assortment

Why does DNA need to replicate exactly for cell division?

To ensure each daughter cell receives a complete and identical set of genetic instructions

Phases of the cell cycle

G1: cell growth - cell contents duplicated (not chromosomes)

S: synthesis - each of the 46 chromosomes duplicated by cell

G2: Cell checks duplicated chromosomes for errors, making any needed repairs

M: mitosis - nucleus divides

Stages of mitosis

prophase, metaphase, anaphase, telophase

Interphase

cell growth and DNA replication

Prophase

Chromosomes condense, spindle fibers form, nucleus envelope breaks down

Metaphase

Chromosomes align at metaphase plate, spindle fibres attach to kinetochores

Anaphase

sister chromatids separate and move towards opposite poles

Telophase

chromosomes reach poles, nuclei form, cytokinesis begins to produce two identical cells