Term 3 Chapter 5.4 & 5.5

Question 1

Difference in binary fission in the prokaryotic and eukaryotic single-celled organisms.

Answer 1

Prokaryotic like bacteria reproduce by making a copy of the DNA and splitting it into two identical offspring or daughter cells however eukaryotic unicellular organism reproduces by mitosis and cell division to produce identical offspring (clones) too.

Question 2

Difference in budding - unicellular and multicellular organism

Answer 2

In unicellular organisms the bud is a single cell. In multicellular organisms the bud grows by cell divisions becoming multicellular before falling into a new organism.

Question 3

Two functions ‘regeneration’ can lead to.

Answer 3

Fragmentation and Vegetative Reproduction.

Question 4

Comparison of sexual and asexual production.

Answer 4

⇒ Advantages/disadvantages of Asexual Reproduction
It allows for rapid populating.
It does not need mates, so does not require mobility.
It is friendly to the environment and handy in case of emergency. It hinders diversity.

⇒ Advantages/disadvantages of Sexual Reproduction
There is diversity in the genetic makeup of the individuals produced by sexual reproduction, since both the parents are involved, the newly formed individuals have the attributes of both. The species produced by sexual reproduction survive more than those produced by asexual reproduction. This is because genetic variations help them to adapt to different environments.
The diversity of life on earth is possible because of the combination of genetic materials from two parents.
Time consuming.

Question 5

Binary fission

Answer 5

Binary Fission: the simplest kind of asexual production

Question 6

Budding

Answer 6

Budding: a process in which an organism develops tiny buds on its body each having the same genetic material as a parent cells

Question 7

Fragmentation

Answer 7

Fragmentation: fragmentation is where the parent body breaks into pieces which each develops into offspring. Example – starfish

Question 8

Parthenogenesis

Answer 8

Parthenogenesis: Parthenogenesis is where a female organisms eggs develop into young without fertilization. Example - some species of snake and wasp

Question 9

Vegetative Reproduction

Answer 9

Vegetative reproduction: vegetative reproduction is where a parent produces offspring without fertilization. Example - cutting of plants

Question 10

Generation Time

Answer 10

Generation Time: The rate of reproduction

Question 11

Relationship between: Genes and heredity.

Answer 11

Heredity is the passing of Genes from parents to offspring.

Question 12

Difference between acquired traits and inherited traits with examples.

Answer 12

Some traits are acquired, not inherited, which means the trait is developed during your lifetime. Acquired traits may be learned traits like speaking different languages or due to the influence of the environment you live in- your skin tone.
Some traits are both inherited and acquired. For example, skin color has both an inherited component and an environmental one.

Question 13

Functions that genes serve

Answer 13

Genes code for proteins that are expressed as your traits; all your traits are described by these genes.

Question 14

The function of the X- and the Y- chromosomes.

Answer 14

A copy of an X and a Y chromosome in each cell is associated with males, whereas females have two copies of X chromosomes in each cell.

Question 15

Explanation of karyotype banding?

Answer 15

The genes appear layered on our chromosomes in a very specific way – like a road map. This is called karyotype banding. If we know where each gene is located, we can find it on anyone’s chromosomes. This is very useful when looking for specific genes that may cause a deadly disease.

Question 16

The definition of the human genome.

Answer 16

Human Genome: All of the human chromosomes and genes

Question 17

The purpose of the human genome project?

Answer 17

The human genome has been mapped. As a result of the mapping of the human genome, during what is known as the human genome project (HGP) we now know there are approximately 20,500 human genes.

Question 18

Summarization of the patterns shown in Mendel’s experiments with height in three steps.

Answer 18

● Parent generation: One true-breeding for regular height ( homozygous dominant-Tall- TT) and the other true-breeding for dwarf height (homozygous recessive- dwarf- tt) and cross-pollinated.

● The first generation: The true-bred cross-pollinated parent generation produced all regular height plants in the ratio of 4:4. The dwarf trait completely disappeared in these first-generation offspring plants.

● The second generation: Allowing the first-generation plants to self-pollinate resulted in the second- generation offspring – 3⁄4 regular and 1⁄4 dwarf pea plants. (Ratio-3:1) The dwarf trait reappeared in the second-generation plants.

Question 19

The three conclusions that Mendel drew from his experiments with pea plants

Answer 19

• Traits were passed down from one generation to the next generation.
• There must be two factors for each possible trait, one factor from each parent.
• Some traits could be masked by the other dominant traits.

Question 20

The uniqueness of the pea plant traits that Gregor Mendel chose to study.

Answer 20

Some plants were tall, and some were short, some had wrinkled pods, and some had smooth pods, some pods were green, and some were yellow, the flowers were white or purple.

Question 21

Differentiate between Phenotype and Genotype

Answer 21

Phenotype is what is visible physically and genotype is what we cannot see. Phenotype may be the genes of black eyes and genotype may be the genes of blue eyes.

Question 22

Differentiate between Recessive and Domain

Answer 22

Dominant trait is always expressed. If there is also one dominant trait, it will be expressed but a recessive trait can only be expressed when there are two of them. Example: having a straight hairline is recessive, while having a widow’s peak (a V-shaped hairline near the forehead) is dominant.

Question 23

Analyse: Why a person with an allele for a particular trait may not have a phenotype that shows the trait.

Answer 23

That person may not have a phenotype that shows the trait because that trait must be recessive, and that person is heterozygous.