Sigma
Which organelles make protein?
Ribosomes
Which of the following organelles controls all the activities within a cell?
Nucleus
What instructions do genes carry?
to make proteins
Tiny tube-like structures made of protein are called
spindle fibres
Which type of cell division is used for growth and repair in multicellular organisms?
Mitosis
Which stage is the longest in the cell cycle?
interphase
In which phase of mitosis do the chromosomes align in the center of the cell?
Metaphase
The phase of mitosis in which the duplicated chromosomes form into an X shape is
prophase
The phase of mitosis in which duplicated chromosomes move apart to opposite ends of the cell is
anaphase
The phase of mitosis in which a nucleolus forms around the chromosomes is
telophase
What is the main advantage of sexual reproduction?
Increases genetic diversity
Asexual reproduction requires
only one parent to produce offspring
Bacteria reproduce asexually by
binary fission
It is an example of asexual reproduction.
Budding in hydra
Stem cells have the potential to
become many different types of cells
How many chromosomes does a normal human gamete contain?
The process of meiosis produces gametes with _____ as body cells.
23
half the number of chromosomes
Describe two key differences between mitosis and meiosis.
Mitosis produces two identical diploid cells, while meiosis produces four genetically unique haploid cells.
Mitosis is used for growth and repair, while meiosis is used for sexual reproduction.
Explain why genetic variation is important for a species' survival.
Genetic variation increases a species' ability to adapt to environmental changes and survive diseases, reducing the risk of extinction.
Can easily respond to environmental changes. If everything is genetically identical, they will respond the same way - they will become diseases and may die.
List two types of asexual reproduction and provide an example for each.
Binary fission (e.g., bacteria)
Budding (e.g., yeast or hydra)
How does fertilization restore the diploid number of chromosomes in an organism?
Fertilization combines two haploid gametes (sperm and egg), each with 23 chromosomes, restoring the diploid number (46 chromosomes in humans).
DNA is made up of four nitrogenous bases. What pair correctly represents the base pairing in a DNA sequence?
Adenine (A) pairs with Thymine (T), Cytosine (C) pairs with Guanine (G)
Which of the following statements about gametes is true?
A) Gametes are diploid cells that contain a full set of chromosomes.
B) Gametes are produced through the process of mitosis.
C) Gametes contain half the number of chromosomes as body cells.
D) Gametes are identical to the parent cell in terms of genetic information.
Gametes contain half the number of chromosomes as body cells.
Which type of cell division is used for growth and repair in multicellular organisms?
Mitosis
Explain the process of cloning and discuss one ethical issue related to reproductive technologies.
Cloning creates a genetically identical copy of an organism using its DNA.
Ethical issue: Cloning raises concerns about genetic diversity, human cloning ethics, and potential health problems in cloned organisms.
Outline the process of meiosis and explain how it ensures genetic diversity in offspring.
Meiosis I separates homologous chromosomes, and Meiosis II separates sister chromatids, resulting in four haploid cells.
Genetic diversity is ensured through crossing over (exchange of genes between homologous chromosomes) and independent assortment (random separation of chromosomes).