Problem 5 - Biology the Easy Way (E-Z Biology)

Question

The sporophyte generation of sea lettuce is (a) haploid (c) diploid (b) monoploid (d) tetraploid

Step-by-Step Solution

Answer

(c) diploid

Step 1: Understand the Generations of Sea Lettuce

Sea lettuce, like many other algae and plants, exhibits a life cycle known as alternation of generations. This cycle includes both a gametophyte and a sporophyte generation.

Step 2: Identify the Chromosome Number

The sporophyte generation of sea lettuce is the phase in which the organism has two sets of chromosomes, meaning that these cells are diploid.

Step 3: Choose the Correct Option

From the given options, the term that best describes the chromosome number of the sporophyte generation is "diploid." Diploid organisms have two sets of chromosomes, one inherited from each parent.

Key Concepts

Sporophyte Generation

In the life cycle of sea lettuce, there are two distinct generations: the sporophyte and the gametophyte. The sporophyte generation is crucial as it represents the stage where spores are produced. These spores are essential for reproduction, allowing for the continuation of genetic material into future generations. In sea lettuce, the sporophyte generation alternates with the gametophyte generation, which is when gametes are produced.
This alternation of generations is a fundamental characteristic of many plants and algae, enabling them to thrive in various environments.

• The sporophyte uses meiosis to produce haploid spores.
• These spores will eventually grow into the gametophyte generation.
• Finally, the gametophyte generation will produce gametes, completing the cycle.

This cyclical nature ensures that both genetic variation and adaptation potential are maximized.

Diploid

The term 'diploid' refers to a cell or an organism possessing two complete sets of chromosomes. In the context of the sea lettuce life cycle, the sporophyte generation is diploid. This means it carries two copies of genetic material, one from each parent organism.
The diploid nature is vital for genetic diversity, as it allows for recombination of genetic material during reproduction.

• Diploid cells undergo mitosis, leading to cell growth and development.
• During the sporophyte phase, cells divide mitotically, maintaining the diploid state.
• This ensures that when sporophytes produce spores through meiosis, there is genetic mixing.

The diploid stage is essential for increasing variation within a species, which helps populations adapt to changing environments.

Sea Lettuce Life Cycle

Sea lettuce, a type of green algae, exhibits a fascinating life cycle known as alternation of generations. This includes distinct gametophyte and sporophyte stages. In sea lettuce, both these generations are free-living, meaning each generation independently carries out its life functions.
The cycle begins with the diploid sporophyte generation.

• The sporophyte undergoes meiosis to produce haploid spores.
• These spores grow into haploid gametophytes.
• Gametophytes will produce gametes.
• These gametes fuse during fertilization to form a diploid zygote.
• The zygote develops into a new sporophyte, completing the cycle.

The alternation between these two generations ensures the propagation and genetic continuity of sea lettuce through successive epochs and environments.