Biology Practical and Cell Division: Scientific Method, Microscopy, Enzymes, and Blood Types

What is the scientific method?

A systematic, evidence-based process used to investigate questions.

What is the purpose of the scientific method?

To provide a structured way to answer questions.

What are the steps of the scientific method?

Question, Research, Hypothesis, Experiment, Analyze, Conclusion, Communicate.

What is peer review?

Evaluation of scientific work by experts in the same field.

What is a double-blind study?

Neither participants nor researchers know key details to prevent bias.

What is a cell?

The basic unit of life.

What does the nucleus do?

Stores genetic material.

What does the ocular lens do?

Magnifies image (10x).

What do objective lenses do?

Provide magnification (4x, 10x, 40x, 100x).

What does coarse adjustment do?

Moves stage quickly for focus.

What does fine adjustment do?

Sharpens image.

What does diaphragm do?

Controls light.

What is the pH range?

0-14.

What is the acid range?

0-6.

What is neutral pH?

7.

What is the base range?

8-14.

What are the main acids in the body?

Hydrogen and CO2.

What is the main base in the body?

Bicarbonate.

What is micropipetting?

Measuring very small liquid amounts.

What are the uses of micropipetting?

Diagnostics, medications, research.

What is diffusion?

Movement from high to low concentration.

What is osmosis?

Water movement across a semipermeable membrane.

What is isotonic?

Equal solute, cell stable.

What is hypotonic?

Cell swells.

What is hypertonic?

Cell shrinks.

What are enzymes?

Proteins that speed reactions.

What do enzymes lower?

Activation energy.

What is a substrate?

Molecule enzyme acts on.

What is the lock and key model?

Perfect fit.

What is the induced fit model?

Enzyme changes shape.

What is denaturation?

Loss of enzyme shape due to heat/pH.

What is mitosis?

Division producing 2 identical cells.

Why does mitosis occur?

Growth and repair.

What happens in prophase of mitosis?

Chromosomes condense, spindle forms.

What happens in metaphase of mitosis?

Chromosomes line up in middle.

What happens in anaphase of mitosis?

Sister chromatids separate.

What happens in telophase of mitosis?

Two nuclei form.

What is cytokinesis?

Cell splits into 2 diploid cells.

What is meiosis?

Division producing gametes.

Why does meiosis occur?

Reduce chromosome number for reproduction.

What happens in prophase I of meiosis?

Crossing over occurs.

What happens in metaphase I of meiosis?

Homologous pairs align.

What happens in anaphase I of meiosis?

Homologous chromosomes separate.

What happens in telophase I of meiosis?

Two haploid cells form.

What is the purpose of meiosis II?

Separate sister chromatids.

What is the final result of meiosis?

4 haploid genetically different cells.

Describe blood type A.

A antigens, anti-B antibodies. Receives A,O. Donates to A,AB.

Describe blood type B.

B antigens, anti-A antibodies. Receives B,O. Donates to B,AB.

Describe blood type AB.

A and B antigens, no antibodies. Universal recipient.

Describe blood type O.

No antigens, anti-A and anti-B antibodies. Universal donor.

What is Rh+?

Has Rh antigen, can receive + or -.

What is Rh-?

No Rh antigen, produces antibodies if exposed.

Does asexual reproduction occur in mitosis or meiosis?

Mitosis.

What is the chromosome count before mitosis?

Diploid (2n).

What is the genetic content after meiosis I?

Haploid with duplicated chromosomes.

What happens after telophase I?

Two haploid cells.

How do final meiosis cells compare to prophase I?

Final are haploid/different; prophase I is diploid.

What happens at the end of meiosis I?

Homologous chromosomes separated.

When do sister chromatids separate?

Mitosis and meiosis II.

What only occurs in meiosis?

Crossing over and independent assortment.

What is the difference between mitosis and meiosis I?

Mitosis produces identical cells; meiosis I reduces chromosomes.

What is the difference between mitosis and meiosis II?

Meiosis II produces haploid cells.

When do homologous chromosomes align?

Metaphase I.

When does independent assortment occur?

Metaphase I.

What happens in a mismatched transfusion?

Agglutination.

What is agglutination?

Antibodies attack RBCs causing clumping.

What is the universal donor?

O-.

What blood type has no clotting with anti-A and anti-B?

Type O.

What causes hemolytic disease?

Rh incompatibility.

When does a baby get hemolytic disease?

Rh- mother, Rh+ baby.

Why can someone receive certain blood types but not others?

Antibodies attack foreign antigens causing clumping.

Does asexual reproduction happen during mitosis or meiosis?

Mitosis

 In animal cells that are about to enter mitosis, how many chromosomes are there?

 Diploid (2n), same number as body cells (46 in humans)

After meiosis I (before meiosis II), what is the genetic content of the cell?

Haploid (n), but chromosomes are still duplicated (sister chromatids attached)

Describe the chromosomal makeup of each daughter cell after telophase I of meiosis

Two haploid cells, each with duplicated chromosomes

 Compare completed meiosis cells with a cell in prophase I

Completed meiosis → haploid and genetically different; Prophase I → diploid with homologous pairs

What happens at the conclusion of meiosis I?

Homologous chromosomes separate, forming two haploid cells

In which processes do sister chromatids separate?

Mitosis (anaphase) and meiosis II (anaphase II)

Which processes occur in meiosis but not mitosis?

Crossing over, independent assortment, homologous chromosome pairing

Identify an image of anaphase I of meiosis

Homologous chromosomes separating (still X-shaped)

Identify an image of anaphase II of meiosis 

 Sister chromatids separating (like mitosis)

Identify an image of prophase of mitosis

Chromosomes condense, not yet lined up

Identify an image of metaphase of mitosis

Chromosomes aligned in the middle (metaphase plate)

Which process happens during meiosis that does not happen during mitosis?

Crossing over and independent assortment

Major difference between mitosis and meiosis I in a diploid organism?

Mitosis separates sister chromatids; meiosis I separates homologous chromosomes

 Major difference between mitosis and meiosis II in a diploid organism?

Mitosis produces diploid cells; meiosis II produces haploid cells

Describe the state of chromosomes during meiosis I

Homologous chromosomes pair, crossing over occurs, chromosomes remain duplicated

During which process do homologous chromosomes align at the metaphase plate?

Metaphase I

During which process does independent assortment occur?

 Metaphase I